[GiNaC-devel] [SCM] GiNaC -- a C++ library for symbolic computations branch, ginac_1-5, updated. release_1-4-0-198-g8bf0597

[Alexei Sheplyakov]

On Fri, Jul 31, 2009 at 02:43:38PM +0200, Jens Vollinga wrote:

> Alexei Sheplyakov schrieb:
>> I'm afraid this code is a bit dangerous.
>>
>> Suppose reader->second corresponds to the serial of some (GiNaC::)function
>> (and not a pointer to a C++ function). ret = GiNaC::function(...) calls
>> eval(), and it might throw an exception. We catch the exception and
>> dereference ->second => oops...
>
> you are right. I fixed it now. Thanks!

I don't think the new variant is any different.

69         // dirty hack to distinguish between serial numbers of functions and real
70         // pointers.
71         try {
72                 GiNaC::function f(reinterpret_cast<unsigned>(reader->second), args);
73                 return f;

eval() is still called here. The compiler has to call ex::ex(const basic&)
ctor in order to convert the value being returned to the correct type (ex).
That ctor calls ex::construct_from_basic(const basic&), and it calls eval()
(which might throw an exception, and so on).

Best regards,
	Alexei